Patent literature 1: U.S. Pat. No. 8,699,371 B2
A system that acquires information from a sensor or the like has been known. For example, Patent literature 1 outputs a signal from a master side to a slave side. According to the signal, data is transmitted from the slave side to the master side.
The inventor of the present disclosure has found the following.
Patent literature 1 performs a signal transmission from the master to the slave and a data transmission from the slave to the master by using the common wiring. In this case, a microcomputer or the like in the master may read a request signal that requests the slave to perform the data transmission as well as the data signal, the request signal being transmitted from the master to the slave.